Phosphorus-free multifunctional additives for lubricants

ABSTRACT

Suitable lubricant additives are the compounds of formulae                    
     wherein the substituents and groups have the following preferred meanings: 
     R 1 =H; R 2 =methyl or tert-butyl; R 3 =tert-butyl; 
     s=0, 1 or 2; 
     R 4 =—A—[(C 6 H 2 )(methyl or tert-butyl)(OH)(tert-butyl)]; 
     A=—CH 2 CH 2 O—(C═O)—CH 2 CH 2 — or —CH 2 CH(CH 3 )—O—(C═O)—CH 2 CH 2 —.

The present invention relates to compounds of formula I and II, whichare suitable as ash-free antiwear additives and antioxidants, tolubricant compositions comprising said compounds as well as to the usethereof.

For operating combustion engines, it has been found advantageous to uselubricants having a low metal content and, therefore, a low ash contentand, in view of exhaust gas catalyst compatibility, also a lowphosphorus content. There is therefore a search for metal-free andphosphorus-free additives or additive combinations which approach thegood antioxidative and wear protection of the zincdialkyldithiophosphates. Some experiments are known to intramolecularlycombine chemical substructures promising different functions as oiladditives.

U.S. Pat. No. 3,676,449 describes 1,3,4-thiadiazole-bridgedbis-thiomethylene-phenols of the formula

which are suitable as antioxidants for materials susceptible tooxidation, in particular polyolefins.

U.S. Pat. No. 4,906,393 describes borates as reaction products of

wherein R₁, R₂, R₃ and R₄are hydrogen or C₁-C₆₀ hydrocarbon, optionallycomprising S, N and/or O; R₅ and R₆ are hydrogen or C₁-C₂₀hydrocarbon,optionally comprising S, N and/or O; R′ is a dimercaptothiadiazole unit;X=0-10, and y+z=3.

U.S. Pat. No. 5,177,212 describes the use of reaction products of2,5-dimercapto-1,3,4-thiadiazole of type a), b) or c) with aliphatic oraromatic aldehyde and alkylated phenol, at a ratio of 1:1:1 to 2:2:1, asantiwear additives and antioxidants for lubricant compositions:

wherein R=H, the terpene radical, a polymer radical (ex poly-α-olefin orepoxidised poly-α-olefin); R₁=H, C₁-C₁₇alkyl, phenyl, alkyl-substitutedphenyl; R₂ and R₄=H, OH or alkyl, either R₂ or R₄ being defined as OH;R₃ and R₅=alkyl, and n=1-2.

This invention relates to compounds of formulae I and II describedhereinafter, which are suitable as ash- and phosphorus-free antiwearadditives and which additionally have an anti-oxidative effect:

In these formulae:

R₁=hydrogen or C₁-C₂₀alkyl;

R₂=hydrogen, C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl, C₇-C₁₀bicycloalkyl, phenylor C₇-C₉phenylalkyl;

R₃=C₁-C₁₈alkyl, C₅-C₁₂cycloalkyl, phenyl or C₇-C₉phenylalkyl;

s=0, 1 or 2;

R₄=C₅-C₂₀alkyl, C₅-C₁₂cycloalkyl, phenyl, naphthyl, C₇-C₉phenylalkyl,which may be interrupted by one or several bivalent radicals from thegroup consisting of —O—, —NR₅—, —S—, —C(═O)—O—, —O—C(═O)—, —C(═O)—NR₅—and —NR₅—C(═O)— or substituted by one or several radicals from the groupconsisting of —OH, —NH₂ and —C(═O)—OH, or is —A—[(C₆H₂)R₂(OH)R₃];

R₅=H or C₁-C₁₈alkyl;

A=C₁-C₂₅alkylene which may be interrupted by one or several bivalentradicals from the group consisting of —O—, —NR₅—, —S—, —C(═O)—O—,—O—C(═O)—, —C(═O)—NR₅— and —NR₅—C(═O)— or substituted by one or severalradicals from the group consisting of —OH, —NH₂ and —C(═O)—OH, at leastone unit —C(═O)—O— or —O—C(═O)— being present.

It is preferred that:

R₁=H;

R₂=H, C₁-C₈alkyl, C₅-C₆cycloalkyl, phenyl, benzyl or 2-norbornyl;

R₃=C₁-C₈alkyl, C₅-C₆cycloalkyl, phenyl, benzyl or 2-norbornyl;

s=0, 1 or 2;

R₄=C₅-C₇cycloalkyl, phenyl, benzyl, C₁-C₁₈alkyl, which may beinterrupted by one or several bivalent radicals from the groupconsisting of —O—, —NH—, —S—, —C(═O)—O—, —O—C(═O)—, —C(═O)—NR₅— and—NR₅—C(═O)— or substituted by one or several radicals from the groupconsisting of —OH and —C(═O)—OH, or is —A—[(C₆H₂)R₂(OH)R₃];

R₅=H or C₁-C₈alkyl;

A=C₁-C₁₈alkylene which may be interrupted by one or several bivalentradicals from the group consisting of —O—, —NR₅—, —S—, —C(═O)—,—O—C(═O)—, —C(═O)—NR₅— and —NR₅—C(═O)— or substituted by one or severalradicals from the group consisting of —OH, —NH₂ and —C(═O)—OH, at leastone unit —C(═O)—O— or —O—C(═O)— being present.

It is particularly preferred that:

R₁=H; R₂=methyl or tert-butyl; R₃=tert-butyl;

s=0, 1 or 2;

R₄=—A—[(C₆H₂)(methyl or tert-butyl)(OH)(tert-butyl)];

A=—CH₂CH₂O—(C═O)—CH₂CH₂— or —CH₂CH(CH₃)—O—(C═O)—CH₂CH₂—.

Very particularly preferred compounds are:

These compounds are suitable as multifunctional antiwear additiveshaving additional anti-oxidative activity for base oils of lubricatingviscosity as well as for fuels. They are phosphorus-free andsubstantially ash-free.

In another of its aspects, this invention relates to compositionscomprising a compound of formula I or II or mixtures thereof incombination with a base oil of lubricating viscosity or with fuels.

A base oil of lubricating viscosity can be used for the preparation oflubricating greases or lubricants and for metal working, gear orhydraulic fluids.

Such lubricating greases or lubricants, metal working, gear andhydraulic fluids are based, for example, on mineral or syntheticlubricants or oils or on mixtures thereof. The skilled person isfamiliar with them, and they are described in the relevant literature,for example in Chemistry and Technology of Lubricants; Mortier, R. M.and Orszulik, S. T. (Editors); 1992 Blackie and Son Ltd. for GB,VCH-Publishers N.Y for U.S., ISBN 0-216-92921-0, see pages 208 et seq.and 269 et seq.; in Kirk-Othmer Encyclopedia of Chemical Technology,fourth Edition 1969, J. Wiley & Sons, New York, Vol. 13, page 533 etseq. (Hydraulic Fluids); Performance Testing of Hydrauic Fluids; R.Tourret and E P. Wright, Hyden & Son Ltd. GB, on behalf of The Instituteof Petroleum London, ISBN 0 85501 317 6; Ullmann's Encyclopedia of Ind.Chem., Fifth Completely revised Edition, Verlag Chemie, DE-Weinheim,VCH-Publishers for U.S., Vol. A 15, page 423 et seq. (lubricants), Vol.A 13, page 165 et seq. (hydraulic fluids).

This invention also relates to a process for improving the performanceproperties of lubricants or lubricating greases, such as motor oil,turbine oil, gear oil, hydraulic or metal working fluids or liquid fuels(diesel or carburettor fuels), which comprises adding at least onecompound of formula I or II to the base oil or fuel to achieve afriction-reducing and/or antioxidative effect. Accordingly, thisinvention also relates to the use of compounds of formula I or II asadditives in motor oils, turbine oils, gear oils, hydraulic fluids,metal working fluids, lubricating greases or diesel or carburettorfuels.

The lubricants are preferably oils and greases, based e.g. on a mineraloil. Oils are preferred.

Another group of lubricants which may be used are vegetable or animaloils, fats, tallows and waxes or their mixtures with each other or theirmixtures with the mentioned mineral or synthetic oils. Vegetable andanimal oils, fats, tallows and waxes are, for example, palmnut oil, palmoil, olive oil, beet oil, rapeseed oil, linseed oil, groundnut oil,soybean oil, cottonseed oil, sunflower oil, pumpkin seed oil, coconutoil, corn oil, castor oil, walnut oil and mixtures thereof, fish oils,tallows of slaughter animals, such as beef tallow, neat's foot oil andbone fat as well as their modified epoxidised and sulfoxidised forms,for example epoxidised soybean oil.

Examples of synthetic lubricants include lubricants based on aliphaticor aromatic carboxylates, polymeric esters, polyalkylene oxides,poly-α-olefins or silicones, on a diester of divalent acids with amonovalent alcohol, e.g. dioctyl sebacate or dinonyl adipate, on atriester of trimethylolpropane with a monovalent acid or with a mixtureof such acids, e.g. trimethylolpropane tripelargonate,trimethylolpropane tricaprylate or mixtures thereof, on a tetraester ofpentaerythritol with a monovalent acid or with a mixture of such acids,e.g. pentaerythritol tetracaprylate, or on a complex ester of monovalentand divalent acids with polyvalent alcohols, for example a complex esterof trimethylolpropane with caprylic and sebacic acid or of a mixturethereof. Particularly suitable are, besides mineral oils, e.g.poly-α-olefins, ester-based lubricants, glycols, polyglycols andpolyalkylene glycols and their mixtures with water.

Metal working fluids and hydraulic fluids can be prepared on the basisof the same substances as those described above for the lubricants. Theyare often also emulsions of such substances with water or other liquids.

The lubricant compositions of this invention are used, for example incombustion engines, e.g. in motor vehicles equipped e.g. with engines ofthe Otto, diesel, two-stroke, Wankel or orbital type.

The compounds of formula I or II are readily soluble in lubricants, inmetal working and hydraulic fluids and are therefore particularlysuitable as additives for lubricants, metal working and hydraulicfluids.

The compositions expediently comprise 0.005 up to 10.0% by weight of thecompounds of formula I or II, preferably 0.01-5.0% by weight, morepreferably 0.01-0.9% weight.

The compounds of formula I or II can be admixed to the lubricants in amanner known per se. The compounds are readily soluble e.g. in oils.They can also be used together with additional additives to prepare aconcentrate or a so-called additive packet which, depending on theconsumption, can be diluted to the concentrations to be used for thecorresponding lubricant.

The compositions of this invention can additionally contain furtheradditives which are added to further improve their basic properties.These additives include: additional antioxidants, metal passivators,rust inhibitors, viscosity index improvers, pour point depressants,dispersants, detergents, other extreme pressure additives, antiwearadditives and friction reducers. Where appropriate, these additives canact synergistically with each other or with the novel compounds. Suchadditives are added in the usual amounts ranging from about 0.01 to10.0% by weight each. Should it still be necessary to add phophorus- ormetal-containing additives, then these additives are preferably added insmall amounts, for example of about 0.01 to 0.1% by weight.

Preparation: The compounds of formulae I and II can be prepared bytransesterifying or esterifying carboxylate- or carboxylic acidchloride-functionalised alkylphenols with alcohol-functionalisedS-alkylmercapto-S/N-heterocycles [e.g. Examples 2, 3, 5, 7, 8, 10, 12,13] or carboxylate- or carboxylic acid chloride-functionalisedS-alkylmercapto-S/N-heterocycles with alcohol-functionalisedalkylphenols [e.g. Example 14].

Typical examples of additional additives are the following:

Examples of phenolic antioxidants:

1.1 Alkylated monophenols, for example 2,6-di-tert-butyl-4-methylphenol,2-tert-butyl-4,6-di-methylphenol, 2,6-di-tert-butyl-4-ethylphenol,2,6di-tert-butyl-4-n-butylphenol, 2,6di-tert-butyl-4-isobutylphenol,2,6-dicyclopentyl-4-methylphenol,2-(1-methylcyclohexyl)-4,6-dimethyl-phenol,2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclohexylphenol,2,6-di-tert-butyl-4-methoxymethylphenol, nonylphenols which are linearor branched in the side chains, for example 2,6-di-nonyl-4-methylphenol,2,4-dimethyl-6-(1′-methylundec-1′-yl)phenol,2,4-dimethyl-6-(1′-methylheptadec-1′-yl)phenol,2,4-dimethyl-6-(1′-methyltridec-1′-yl)phenol and mixtures thereof.

1.2 Alkylthiomethylphenols, for example2,4-dioctylthiomethyl-6-tert-butylphenol,2,4-dioctylthiomethyl-6-methylphenol,2,4-dioctylthiomethyl-6-ethylphenol,2,6-di-dodecylthiomethyl-4-nonylphenol.

1.3 Hydroquinones and alkylated hydroquinones, for example2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone,2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol,2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole,3,5-di-tert-butyl-4-hydroxyanisole, 3,5-di-tert-butyl-4-hydroxyphenylstearate, bis-(3,5-di-tert-butyl-4-hydroxyphenyl) adipate.

1.4 Tocopherols, for example α-, β-, γ- or δ-tocopherol and mixturesthereof (vitamin E).

1.5 Hydroxylated thiodiphenyl ethers, for example2,2′-thiobis(6-tert-butyl-4-methylphenol), 2,2′-thiobis(4-octylphenol),4,4′-thiobis(6-tert-butyl-3-methylphenol),4,4′-thiobis(6-tert-butyl-2-methylphenol),4,4′-thiobis(3,6-di-sec-amylphenol),4,4′-bis(2,6-dimethyl-4-hydroxyphenyl) disulfide.

1.6 Alkylidenebisphenols, for example2,2′-methylenebis(6-tert-butyl-4-methylphenol),2,2′-methylenebis(6-tert-butyl-4-ethylphenol),2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)-phenol],2,2′-methylenebis(4-methyl-6-cyclohexylphenol),2,2′-methylenebis(6-nonyl-4-methylphenol),2,2′-methylenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(4,6-di-tert-butylphenol),2,2′-ethylidenebis(6-tert-butyl-4-isobutylphenol),2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],2,2′-methylenebis[6(α,α-dimethylbenzyl)-4-nonylphenol],4,4′-methylenebis-(2,6-di-tert-butylphenol),4,4′-methylenebis(6-tert-butyl-2-methylphenol),1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,1,1-bis(5-tert-butyl-4-hydroxy-2-methyl-phenyl)-3-n-dodecylmercaptobutane,ethylene glycol bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate],bis(3-tert-butyl-4-hydroxy-5-methyl-phenyl)dicyclopentadiene,bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate,1,1-bis-(3,5-dimethyl-2-hydroxyphenyl)butane,2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane,2,2-bis(5-tert-butyl-4-hydroxy2-methylphenyl)-4-n-dodecylmercaptobutane,1,1,5,5-tetra(5-tert-butyl-4-hydroxy-2-methylphenyl)pentane.

1.7 O- , N- and S-benzyl compounds, for example3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether,octadecyl-4-hydroxy-3,5-dimethylbenzylmercaptoacetate,tridecyl-4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate,tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine,bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate,bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide,isooctyl-3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate.

1.8 Hydroxybenzylated malonates, for exampledioctadecyl-2,2-bis-(3,5-di-tert-butyl-2-hydroxybenzyl)malonate,di-octadecyl-2(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate,didodecylmercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate,bis[4-(1,1,3,3-tetramethylbutyl)phenyl]-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate.

1.9 Aromatic hydroxybenzyl compounds, for example1,3,5-tris-(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol.

1.10 Triazine compounds, for example2,4-bis(octylmercapto)-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine,2,4,6-tris-(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)isocyanurate,1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)isocyanurate,2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hexahydro-1,3,5-triazine,1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)-isocyanurate.

1.11 Benzylphosphonates, for exampledimethyl-2,5-di-tert-butyl-4-hydroxybenzylphosphonate,diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,dioctadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,dioctadecyl-5-tert-butyl-4-hydroxy3-methylbenzylphosphonate, the calciumsalt of the monoethyl ester of3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid.

1.12 Acylaminophenols, for example 4-hydroxylauranilide,4-hydroxystearanilide, octylN-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate.

1.13 Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, n-octanol,i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane, 4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.14 Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acidwith mono- or polyhydric alcohols, e.g. with methanol, ethanol,n-octanol, i-octanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethyleneglycol, diethylene glycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl) isocyanurate, N,N′-bis-(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.15 Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid withmono- or polyhydric alcohols, e.g. with methanol, ethanol, octanol,octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.16 Esters of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with mono-or polyhydric alcohols, e.g. with methanol, ethanol, octanol,octadecanol, 1,6-hexanediol, 1,9-nonanediol, ethylene glycol,1,2-propanediol, neopentyl glycol, thiodiethylene glycol, diethyleneglycol, triethylene glycol, pentaerythritol,tris(hydroxyethyl)isocyanurate, N,N′-bis(hydroxyethyl)oxamide,3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,trimethylolpropane,4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.

1.17 Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid e.g.N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine,N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)-hydrazine.

1.18. Ascorbic acid (vitamin C)

1.19. Aminic antioxidants: for exampleN,N′-di-isopropyl-p-phenylenediamine,N,N′-di-sec-butyl-p-phenylenediamine,N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine,N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine,N,N′-bis(1-methylheptyl)-p-phenylenediamine,N,N′-dicyclohexyl-p-phenylenediamine, N,N′-diphenyl-p-phenylenediamine,N,N′-bis(2-naphthyl)-p-phenylenediamine,N-isopropyl-N′-phenyl-p-phenylenediamine,N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine,N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine,N-cyclohexyl-N′-phenyl-p-phenylenediamine,4-(p-toluenesulfamoyl)diphenylamine,N,N′-dimethyl-N,N′-di-sec-butyl-p-phenylenediamine, diphenylamine,N-allyldiphenylamine, 4-isopropoxydiphenylamine,N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine,N-phenyl-2-naphthylamine, octylated diphenylamine, for examplep,p′-di-tert-octyldiphenylamine, 4-n-butylaminophenol,4-butyrylaminophenol, 4-nonanoylamino-phenol, 4-dodecanoylaminophenol,4-octadecanoylaminophenol, bis(4-methoxyphenyl)amine,2,6-di-tert-butyl-4-dimethylaminomethylphenol,2,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane,N,N,N′,N′-tetramethyl-4,4′-diaminodiphenylmethane,1,2-bis[(2-methylphenyl)amino]ethane, 1,2-bis(phenylamino)propane,(o-tolyl)biguanide, bis[4-(1′, 3′-dimethylbutyl)phenyl]amine,tert-octylated N-phenyl-1-naphthylamine, a mixture of mono- anddialkylated tert-butyl/tert-octyl-diphenylamines, a mixture of mono- anddialkylated nonyldiphenylamines, a mixture of mono- and dialkylateddodecyldiphenylamines, a mixture of mono- and dialkylatedisopropyl/isohexyldiphenylamines, a mixture of mono- and dialkylatedtert-butyldiphenylamines, 2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine,phenothiazine, a mixture of mono- and dialkylatedtert-butyl/tert-octylphenothiazines, a mixture of mono- and dialkylatedtert-octyl-phenothiazines, N-allylphenothiazine,N,N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene,N,N-bis-(2,2,6,6-tetramethyl-piperid-4-yl-hexamethylenediamine,bis(2,2,6,6-tetramethylpiperid-4-yl)sebacate,2,2,6,6-tetramethylpiperidin-4-one, 2,2,6,6-tetramethylpiperidin-4-ol.

Examples of other antioxidants:

Aliphatic or aromatic phosphites, esters of thiodipropionic acid or ofthiodiacetic acid, or salts of dithiocarbamic or dithiophosphoric acid,2,2,12,12-tetramethyl-5,9-dihydroxy-3,7,11-trithiatridecane and2,2,15,15-tetramethyl-5,12-dihydroxy-3,7,10,14-tetrathiahexadecane.

Examples of metal deactivators, for example for copper, are:

a) Benzotriazoles and the derivatives thereof, for example2-mercaptobenzotriazole, 2,5-dimercaptobenzotriazole, 4- or5-alkylbenzotriazoles (e.g. tolutriazole) and the derivatives thereof,4,5,6,7-tetrahydrobenzotriazole and 5,5′-methylenebisbenzotriazole;Mannich bases of benzotriazole or tolutriazole, e.g.1-[bis(2-ethylhexyl)aminomethyl)tolutriazole and1-[bis(2-ethylhexyl)aminomethyl)benzotriazole; andalkoxyalkylbenzotriazoles such as 1-(nonyloxymethyl)benzotriazole,1-(1-butoxyethyl)benzotriazole and 1-(1-cyclohexyloxybutyl)tolutriazole.

b) 1,2,4-Triazoles and the derivatives thereof, for example 3-alkyl(oraryl)-1,2,4-triazoles, and Mannich bases of 1,2,4-triazoles, such as1-[bis(2-ethylhexyl)aminomethyl-1,2,4-triazole;alkoxyalkyl-1,2,4-triazoles such as 1-(1-butoxyethyl)-1,2,4-triazole;and acylated 3-amino-1,2,4-triazoles.

c) Imidazole derivatives, for example4,4′-methylenebis(2-undecyl-5-methylimidazole) andbis[(N-methyl)imidazol-2-yl]carbinol octyl ether.

d) Sulfur-containing heterocyclic compounds, for example2-mercaptobenzothiazole, 2,5-dimercapto-1,3,4-thiadiazole andderivatives thereof; and3,5-bis[di(2-ethylhexyl)aminomethyl]-1,3,4-thiadiazolin-2-one.

e) Amino compounds, for example salicylidenepropylenediamine,salicylaminoguanidine and the salts thereof.

Examples of rust inhibitors are:

a) Organic acids, their esters, metal salts, amine salts and anhydrides,for example alkyl- and alkenylsuccinic acids and their partial esterswith alcohols, diols or hydroxycarboxylic acids, partial amides ofalkyl- and alkenylsuccinic acids, 4-nonylphenoxyacetic acid, alkoxy- andalkoxyethoxycarboxylic acids such as dodecyloxyacetic acid,dodecyloxy(ethoxy)acetic acid and the amine salts thereof, and alsoN-oleoylsarcosine, sorbitan monooleate, lead naphthenate,alkenylsuccinic anhydrides, for example dodecenylsuccinic anhydride,2-(2-carboxyethyl)-1-dodecyl-3-methylglycerol and the salts thereof, inparticular the sodium salts and triethanolamine salts.

b) Nitrogen-containing compounds, for example:

i. Primary, secondary or tertiary aliphatic or cydoaliphatic amines andamine salts of organic and inorganic acids, for example oil-solublealkylammonium carboxylates, and also1-[N,N-bis(2-hydroxyethyl)amino]-3-(4-nonylphenoxy)propan-2-ol.

ii. Heterocyclic compounds, for example: substituted imidazolines andoxazolines, and 2-heptadecenyl-1-(2-hydroxyethyl)imidazoline.

c) Phosphorus-containing compounds, for example: Amine salts ofphosphoric acid partial esters or phosphonic acid partial esters, andzinc dialkyldithiophosphates.

d) Sulfur-containing compounds, for example: bariumdinonylnaphthalenesulfonates, calcium petroleum sulfonates,alkylthio-substituted aliphatic carboxylic acids, esters of aliphatic2-sulfocarboxylic acids and the salts thereof.

e) Glycerol derivatives, for example: glycerol monooleate,1-(alkylphenoxy)-3-(2-hydroxy-ethyl)glycerol,1-(alkylphenoxy)-3-(2,3dihydroxypropyl)glycerol and2-carboxyalkyl-1,3-dialkylglycerol.

Examples of viscosity index improvers are:

Polyacrylates, polymethacrylates, vinylpyrrolidone/methacrylatecopolymers, polyvinylpyrrolidones, polybutenes, olefin copolymers,styrene/acrylate copolymers and polyethers.

Examples of pour-point depressants are:

Poly(meth)acrylates, ethylene/vinyl acetate copolymer, alkylpolystyrenes, fumarate copolymers, alkylated naphthalene derivatives.

Examples of dispersants/surfactants are:

Polybutenylsuccinic amides or -imides, polybutenylphosphonic acidderivatives and basic magnesium, calcium and barium sulfonates and basicmagnesium, calcium and barium phenolates.

Examples of extreme pressure and antiwear additives are:

Sulfur- and/or phosphorus- and/or halogen-containing compounds, forexample chlorinated paraffins, sulfurised olefins or vegetable oils(soybean oil and rapeseed oil), alkyl- or aryl-di- or -trisulfides, zincdialkyldithiophosphates, such as zinc-bis(2-ethylhexyl)dithiophosphate,zinc dithiocarbamates, such as zinc diamyldithiocarbamate, molybdenumphosphorodithioates, molybdenum dithiocarbamates, triarylphosphates,such as tritolylphosphate, tricresylphosphate, isopropylphenylphosphate, amine salts of mono- or dialkylphosphoric acids, e.g.the amine salts of mono/di-hexylphosphate, amine salts ofalkylphosphonic acids, such as the amine salt of methylphosphonic acid,triaryl phosphites, e.g. tris[nonylphenyl]phosphite, dialkyl phosphites,such as dioctyl phosphite, triaryl monothiophosphates, e.g. triphenylthionophosphate or tris-[isononylphenyl]thionophosphate ortert-butylated triphenyl thionophosphates, substituted trialkyl mono- ordithiophosphates, for example[(diisopropoxyphosphinothioyl)thio]propionate orbutylene-1,3bis[(diisobutoxyphosphinothioyl)propionate],trithiophosphates, such as trithiophosphoric acid,S,S,S-tris(isooctyl-2-acetate), amine salts of3-hydroxy-1,3-thiaphosphetane-3-oxide, benzotriazoles or the derivativesthereof, e.g. bis(2-ethylhexyl)aminomethyltolutriazole,dithiocarbamates, such as methylene-bis-dibutyldithiocarbamate,derivatives of 2-mercaptobenzothiazole, e.g.1-[N,N-bis(2-ethylhexyl)aminomethyl]-2-mercapto-1H-1,3-benzothiazole,derivatives of 2,5-dimercapto-1,3,4-thiadiazole, such as2,5-bis(tert-nonylditdithio)-1,3,4-thiadiazole.

Examples of frictional coefficient reducers are, for example, lard oil,oleic acid, tallow, rapeseed oil, sulfurised fats, amines. Otherexamples are cited in EP-A-565487.

Examples of special additives for use in water/oil metal working andhydraulic fluids are:

Emulsifiers: petroleum sulfonates, amines, such as polyethoxylated fattyamines, nonionic surface active substances; buffers: alkanolamines;biocides: triazines, thiazolinones, trisnitromethane, mopholine, sodiumpyridene ethol; processing speed improvers: calcium sulfonates andbarium sulfonates;

Examples of fuel additives:

Such additives are described in Kirk-Othmer, Encyclopedia of ChemicalTechnology, Vol. 12, 1994. They are mainly gasoline and dieseladditives:

Gasoline: aminic antioxidants, in particular para-phenylenediamines, orphenolic antioxidants, e.g. 2,6-di-tert-butylphenol (as describedabove); metal deactivators, in particularN,N′-disalicylidene-1,2-propane, benzotriazole, EDTA; rust inhibitors,for example carboxylic acids, sulfonates, amines or amine salts;dispersants, e.g. esters, amines of high molecular weight, Mannichbases, succinimides, boronated succinimides; detergents, for examplefatty acid amides, non-polymeric amines, polybutene succinimides,polyether amines, low molecular weight amines, sulfonates, salicylicacid derivatives; demulsifiers, for example long-chain alcohols orphenols containing polyethylene or polybutylene groups; antiknockadditives, for example manganese methylcyclopentadienyltricarbonyl,oxygen compounds, e.g. esters of vegetable oils, ethers, alcohols forimproving the burning behaviour.

Diesel fuels: ignition improvers (cetane improvers), e.g. alkylnitrates, ether nitrates, alkyl diglycol nitrates, organic peroxides;stabilisers, in particular for cracked diesel: amines and otherN-containing compounds which act as radical interceptors; rustinhibitors, as described above;

detergents as described above; oxygen compounds as described above; coldflow improvers, i.e. for example pour point depressants (see above),cloud point depressants or so-called operability additives (OA), whichare polymeric multicomponent systems improving, inter alia, the filterflow behaviour.

The starting products are known per se and/or their preparation isdescribed in the following Examples [e.g. Examples 1, 4, 6, 9, 11].

EXAMPLES

This invention is illustrated by the following Examples. Parts orpercentages are by weight, unless otherwise stated.

Example 1

70 g (1.2 mol) of propylene oxide are added dropwise over 30 min at 35°C. to a suspension consisting of 172 g (1 mol) of2-mercaptobenzothiazole and 16.1 g (50 mmol) of tetrabutylammoniumbromide in 900 ml of toluene, and the reaction is allowed to go tocompletion over 4 hours at 40° C. This mixture is then extracted twicewith about 100 ml of 2N NaOH solution and washed with 5×100 ml of water(→pH 7-8). The organic phase is concentrated by evaporation and dried atreduced pressure (80° C./about 0.03 mbar), giving 227 g of a clear, palebrown oil of medium viscosity (about 100% of theory) [75235-71-1].

Elemental analysis: 53.36% C (calculated 53.31); 4.92% H (calculated4.92); 6.09% N (calculated 6.22); 28.56% S (calculated 28.46).

Example 2

166 g (0.7 mol) of the product of Example 1 [75235-71-1], dissolved in100 ml of toluene, are added dropwise over 2 hours at 135-140° C. to amelt consisting of 204.7 g (0.7 mol) of Metilox® (Ciba SpecialtyChemicals) *) and 8.7 g (35 mmol) of dibutyltin oxide, distilling offtoluene and methanol at the same time. After the addition is complete,the mixture is allowed to react for 4 hours at 135-140° C., while atotal of about 50 ml of toluene is added dropwise and distilled off atthe same time. After adding another 3.5 g (14 mmol) of dibutyltin oxide,the reaction is allowed to go to completion over another 4 hours at135-140° C. (+toluene, −toluene/methanol).—Unreacted METILOX (about 103g, 0.35 mol) is removed by distillation at reduced pressure (140°C./about 0.03 mbar). The remaining yellow oil of medium viscosity isdissolved in about 400 ml of special-boiling point spirit (b.p. 80-10°C.), extracted twice with about 100 ml of 2N NaOH solution and washedwith 3×c. 100 ml of water (→pH 7). The organic phase is clarified byfiftration through a small amount of filter aid (Hyflo®), concentratedby evaporation and dried at reduced pressure (140° C./c. 0.03 mbar),giving 224 g of a viscous, pale orange and clear oil (66% of theory).

Elemental analysis: 64.75% C (calculated 66.77); 7.42% H (calculated7.26); 3.22% N (calculated 2.88); 14.26% S (calculated 13.20).

*) methyl β-(3.5-di-tert-butyl-4-hydroxyphenyl)propionate [6386-38-5].

Example 3

In the same manner as in Example 2, 22.15 g (90 mmol) of methyl-METILOX*) are reacted with 20.3 g (90 mmol) of the product of Example 1[75235-71-1] in the presence of a catalytic amount of dibutyltin oxide(1.12 g+0.6 g, 6.9 mmol), giving 27.9 g of a brown oil of high viscosity(70% of theory).

Elemental analysis: 64.51% C (calculated 64.83); 6.76% H (calculated6.80); 3.2% N (calculated 3.15); 14.06% S (calculated 14.42).

*) methyl β-(5-tert-butyl-4hydroxy-3-methylphenyl)propionate[6386-39-6].

Example 4

125 g (1.0 mol) of 2-bromoethanol are added dropwise over 1.5 hours at30-40° C. to an emulsion consisting of 172 g (1.0 mol) of2-mercaptobenzothiazole and 121.4 g (1.2 mol) of triethylamine in 1 l oftoluene. This mixture is then stirred for 1.5 hours at 30° C. and for2.5 hours at 70 C. The fine suspension is washed with 2×500 ml of water,200 ml of 2N NaOH solution and again with water (pH 7). Concentration byevaporation and drying at reduced pressure (100° C./c. 0.03 mbar) gives192 g of a brown oil (91% of theory). This crude product [4665-63-8] isthen further reacted directly (e.g. in Example 5).

Example 5

In the same manner as in Examples 2 and 3, 26.3 g (90 mmol) of METILOXare reacted with 19 g (90 mmol) of the product of Example 1 in thepresence of a catalytic amount of dibutyltin oxide (1.7 g, 7 mmol). Thecrude product is preliminarily purified by chromatography over 200 g ofsilica gel (toluene/ethyl acetate) and is recrystallised from ethanol(c. 190 ml), giving 22 g of a white crystalline product; m.p. 108-111°C. (52% of theory).

Elemental analysis: 66.00% C (calculated 66.21); 7.29% H (calculated7.05); 2.94% N (calculated 2.97); 13.59% S (calculated 13.59).

Example 6

A solution of 76.7 g (1.32 mol) of propylene oxide in 50 ml oftetrahydrofuran is added dropwise over 1 hour at 30-35° C. to asuspension consisting of 66 g (0.44 mol) of2,5-dimercapto-1,3,4-thiadiazole [1072-71-5] and 7.1 g (22 mmol) oftetrabutylammonium bromide (TBAB) in 270 ml of tetrahydrofuran. Thereaction is then allowed to go to completion over 1 hour at 40° C. Thedark solution is concentrated by evaporation and the dark oil (c. 130 g)is eluted by chromatography over 500 g of silica gel (toluene/ethylacetate). The fractions of the main product are concentrated byevaporation and dried at reduced pressure (120° C./c. 0.03 mbar), giving97.0 g of an orange viscous oil (83% of theory) [107641-99-6].

Elemental analysis: 36.50% C (calculated 36.07), 5.34% H (calculated5.30); 10.58% N (calculated 10.52), 36.52% S (calculated 36.10).

Example 7

About 25 ml (180 mmol) of triethylamine are added dropwise over 25 minat 5-10° C. to a solution of 16 g (60 mmol) of the product of Example 6[107641-99-6] and c. 53 g (180 mmol) of METILOX-acid chloride *) in 240ml of toluene, and the reaction is allowed to go to completion over 4.5hours at 30-40° C. The turbid orange reaction mixture is washed with 500ml of water, then with 100 ml of 2N NaOH solution and again with water(→pH 7-8) and is then concentrated by evaporation. The crude product (c.70 g) is purified by column chromatography over 500 g of silica gel(hexane/toluene/ethyl acetate). The fractions of the main product areconcentrated by evaporation and dried at reduced pressure (120° C./c.0.03 mbar), giving 17.8 g of a yellow tacky resin (38% of theory).

Elemental analysis: 64.42% C (calculated 64.09); 8.06% H (calculated7.94); 3.47% N (calculated 3.56); 11.74% S (calculated 12.22).

*) β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid chloride[3062-64-4].

Example 8

The tert-butyl/methyl analogue to Example 7 is obtained in a manneranalogous to that of Examples 2, 3 and 5 by catalysedtransesterification of 2 equivalents of methyl-METILOX *) with theproduct of Example 6. This gives 8.0 g of a brown tacky resin (c. 20% oftheory).

Elemental analysis: 61.04% C (calculated 61.51); 7.45% H (calculated7.17); 3.94% N (calculated 3.99); 13.48% S (calculated 13.68).

*) methyl β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionate[6386-39-6].

Example 9

94.6 g (0.6 mol) of methyl bromoacetate are added dropwise over 1 hourat 0-5° C. to a solution of 88 g (0.5 mol) of 2-mercaptobenzothiazoleand 108 g of sodium methanolate 30% (0.6 mol) in 850 ml of methanol.This mixture is stirred at room temperature for 1 hour. Afterconcentrating the mixture by evaporation and dissolving it again in 400ml of toluene, it is washed with 3×100 ml of unsaturated sodium chloridesolution until neutral (pH c. 6). The toluene phase is concentrated byevaporation, giving 131 g of a pale orange oil. This crude product isrecrystallised from hexane (c. 1200 ml), giving 102 g of a whitecrystalline product; m.p. 74-76° C. (86% of theory) [24044-87-9].

The product is further reacted in this quality (e.g. in Example 14).

Example 10

In the same manner as in Examples 2, 3, 5 and 8, 29.4 g (90 mmol) ofmethyl 3,5-bis(tert-butyl)-4-hydroxybenzylthioacetate [51511-20-7] arereacted with 16.9 g (80 mmol) of the product of Example 1[4665-63-8] inthe presence of a catalytic amount of dibutyltin oxide (0.5 g, 9 mmol).The crude product is purified twice by chromatography over 550 g and 300g, respectively, of silica gel (hexane—toluene—ethyl acetate), giving8.8 g of a yellow oil of high viscosity (22% of theory).

Elemental analysis: 62.48% C (calculated 61.99); 7.01% H (calculated6.60); 2.75% N (calculated 2.78); 19.02% S (calculated 19.09).

Example 11

253 g (1.0 mol) of Glydexx® (Exxon) N 10 [Exxon Chemicals: 52636-92-7]are added dropwise over 30 min at 60° C. to a suspension consisting of172 g (1.0 mol) of 2-mercaptobenzothiazole and 5 ml of triethylamine in1.5 l of toluene. This mixture is then heated over 15 min to 80° C. andis stirred for 3 hours at this temperature. The toluene solution is thenwashed with 2×50 ml of 1N NaOH solution and with 4×50ml of water untilneutral (pH 7). The organic phase is clarified by filtration through asmall amount of filter aid (HYFLO). Concentration by evaporation anddrying at reduced pressure (100° C./c. 0.03 mbar) gives 405 g (c. 100%of theory) of a clear oil of medium viscosity; n_(D) ²⁰:1.5578.

Elemental analysis: 60.95% C (calculated 60.73); 7.63% H (calculated7.39); 3.53% N (calculated 3.54); 15.80% S (calculated 16.21).

Example 12

6.7 g (66 mmol) of triethylamine are added dropwise over 15 min at 0-10°C. to a solution of 23.7 g (60 mmol) of the product of Example 11 and18.7 g (63 mmol) of METILOX acid chloride [3062-64-4] in 200 ml oftoluene. This mixture is stirred at room temperature for 3 hours. Thebrown suspension is then filtered and the filtrate is washed with 1×100ml of 2N sodium hydroxide solution and water until neutral and is thenconcentrated by evaporation. The crude product (c. 45 g) is purified bychromatography over 500 g of silica gel (hexane/toluene/ethyl acetate).The fractions with the main product are concentrated by evaporation anddried at reduced pressure (100° C./c.0.03 mbar), giving 21 g of anorange oil of high viscosity (53% of theory).

Elemental analysis: 67.99% C (calculated 67.75); 8.30% H (calculated8.14); 2.07% N (calculated 2.14); 8.75% S (calculated 9.78).

Example 13

11.1 g (0.11 mol) of triethylamine are added dropwise over 25 min at0-10° C. to a solution of 38.4 g (0.1 mol) of III *) and 31.2 g (0.105mol) of METILOX acid chloride [3062-64-4] in 200 ml of toluene, and thereaction is then allowed to go to completion over 2 hours at 30° C. Thismixture is diluted at room temperature with 100 ml of hexane and is thenfiltered and concentrated by evaporation. The crude product (a brownoil, c. 72 g) is purified by column chromatography over about 500 ml ofsilica gel (hexane/toluene/ethyl acetate). The fractions of the mainproduct are concentrated by evaporation and dried at reduced pressure(100° C./c. 0.03 mbar), giving 46.2 g of a highly viscous oil (72% oftheory).

Elemental analysis: 66.7% C (calculated 67.14); 8.49% H (calculated8.30); 2.28% N (calculated 2.17); 15.03% S (calculated 14.93).

*) see EP 166 696, Ex.13 (using tert-dodecyl)

Example 14

A suspension consisting of 23.8 g (90 mmol) of IV *), 21.5 g (90 mmol)of the product of Example 9 **) and 1.7 g of dibutyltin oxide in 50 mlof toluene is slowly heated to 135-140° C., distilling off the tolueneat the same time. Toluene is then continuously added dropwise at thistemperature and is removed by distillation together with the releasedmethanol. Another 1.7 g of dibutyltin oxide are added after about 4hours and then again after 5 hours. After 8 hours, the mixture isconcentrated by evaporation and purified by column chromatography over500 g of silica gel (toluene/ethyl acetate). The fractions of the mainproduct are concentrated by evaporation and dried at reduced pressure(100° C./c. 0.03 mbar, c. 30 min), giving 9.4 g of a highly viscousyellow oil (22% of theory).

Elemental analysis: 66.53% C (calculated 66.21); 7.29% H (calculated7.05); 2.95% N (calculated 2.97); 13.71% S (calculated 13.59).

*) [152211-02-4]; **)[24044-87-9].

Example 15

Antiwear test: To test the suitability as antiwear additive, the ASTMstandard method D-2783-81 is applied using a Shell four-ball tester. Thebase oil used is Stock 305, of Mobil, to which the compound according tothe respective Example cited is added in the amount indicated in TableI. The average wear scar diameter WSD (in mm) is determined at a 40 kgload and at 1440 rpm after 1 hour of operation at 100° C. The resultsobtained are compiled in Table I.

TABLE I Additive amount [% by Compound of Example weight] WSD [mm] baseoil — 2.32  2 1.0 0.68  3 1.0 0.77  5 1.0 0.77  7 1.0 0.74  8 1.0 0.6413 1.0 0.75 14 1.0 0.76

What is claimed is:
 1. A compound of the formula

wherein R₂=hydrogen, C₁-C₁₈alkyl, C₅-C_(12c)ycloalkyl,C₇-C₁₀bicycloalkyl, phenyl or C₇-C₉phenylalkyl; R₃=C₁-C₁₈alkyl,C₅-C₁₂cycloalkyl, phenyl or C₇-C₉phenylalkyl; s=0, 1 or 2;R₄=C₅-C₂₀alkyl, C₅-C₁₂cycloalkyl, phenyl, naphthyl, C₇-C₉phenylalkyl,which may be interrupted by one or several bivalent radicals selectedfrom the group consisting of —O—, —NR₅—, —S—, —C(═O)—O—, —O—C(═O)—,—C(═O)—NR₅— and —NR₅—C(═O)— or substituted by one or several radicalsselected from the group consisting of —OH, —NH₂ and —C(═O)OH, or is—A—((C₆H₂)R₂(OH)R₃); R₅=H or C₁-C₁₈alkyl; A=C₁-C₂₅alkylene which may beinterrupted by one or several bivalent radicals selected from the groupconsisting of —O—, —NR₅—, —S—, —C(═O)—O—, —O—C(═O)—, —C(═O)—NR₅— and—NR₅—C(═O)— or substituted by one or several radicals selected from thegroup consisting of —OH, —NH₂ and —C(═O)—OH, at least one unit —C(═O)—O—or —O—C(═O)— being present.
 2. A compound according to claim 1, whereinR₂=methyl or tert-butyl; R₃=tert-butyl; R₄=—A—((C₆H₂)(methyl ortert-butyl)(OH)(tert-butyl)); and A=—CH₂CH₂O—(C═O)—CH₂CH₂— or—CH₂CH(CH₃)—O—(C═O)—CH₂CH₂—.
 3. A compound according to claim 1, whereinR₂=H, C₁-C₈alkyl, C₅-C₆cycloalkyl, phenyl, benzyl or 2-norbornyl;R₃=C₁-C₈alkyl, C₅-C₆cycloalkyl, phenyl, benzyl or 2-norbornyl;R₄=C₅-C₇cycloalkyl, phenyl, benzyl, C₁-C₁₈alkyl, which may beinterrupted by one or several bivalent radicals from the groupconsisting of —O—, —NH—, —S—, —C(═O)—O—, —O—C(═O)—, —C(═O)—NR₅— and—NR₅—C(═O)— or substituted by one or several radicals from the groupconsisting of —OH and —C(═O)—OH, or is —A—[(C₆H₂)R₂(OH)R₃] R₅=H orC₁-C₈alkyl; A=C₁-C₁₈alkylene which may be interrupted by one or severalbivalent radicals from the group consisting of —O—, —NR₅—, —S—,—C(═O)—O—, —O—C(═O)—, —C(═O)—NR₅— and —NR₅—C(═O)— or substituted by oneor several radicals from the group consisting of —OH, —NH₂ and—C(═O)—OH, at least one unit —C(═O)—O— or —O—C(═O)— being present. 4.Compounds of formulae:


5. A composition, which comprises a compound of formula II according toclaim 1 in combination with a base oil of lubricating viscosity or withfuels.
 6. A concentrate, which comprises an oil and at least onecompound according to claim
 1. 7. A process for improving theperformance properties of lubricants, lubricating greases or liquidfuels, which comprises adding at least one compound of formula IIaccording to claim 1 thereto.